Much of Kansas was once covered in a sea, and that sea once had a sandy beach. When that sand was glued together with calcium carbonate, it created a hard formation called a concretion. The loose sand around concretions eventually erode away, but the hard lumps of glued-together sand remain, leaving behind unusual natural sculptures distinguished enough to make visitors stop and puzzle over them–large rock formations sprouting out of the Kansas prairie like, well, mushrooms.

The concretions at this park have been getting visitors for a long time. The sands within them, which are part of the Dakota Formation, are left over from the beaches of the Cretaceous Period, which was 144 to 66 million years ago. Indians, explorers, trail riders, emigrant settlers–many people have stopped by to pay their respects to the mushroom rocks. Ellsworth County Historical Society recognized their importance and built a road to see them, and in 1965, Mushroom Rock became a state park.

The formations’ ability to fascinate visitors for centuries is documented by historic vandalism.

This free park is small–only 5 acres–and the concretions are accessible on foot, though the footpaths are narrow in places and were extremely muddy and slippery the day we visited. The formations are fascinating and beautiful, and I’m particularly drawn to the idea of connecting with centuries of visitors who stood in the same spots, staring at the same rock formations. It’s a quick, kid-friendly stop, too.

Pulpit Rock formation, which, incidentally, is on the opposite end of the park from Devil’s Oven formation.

The state website includes a downloadable guide, and because we found cellphone service to be spotty in the area, it is helpful to download it ahead of time. Although they’ll be fun to visit at any time, the park was especially beautiful in late May, when wildflowers are blooming all around the park.